A computational study, in the framework of statistical kinetic theories, of the reaction of Ca2+ with urea has been carried out. The kinetically preferred products are NH3 + [ CaOCNH](2+), which are the fifth products in order of stability. The second kinetically preferred products are [CaNH2+] + [NH2CO](+), followed by [CaNH3](2+) + HNCO, whereas the most stable ones, NH4+ + [CaNCO](+) and NH4+ + [CaOCN](+), appear only in residual quantities. These estimates are in agreement with the experimental evidence and provide a suitable mechanism to understand the competition between Coulomb explosion and neutral loss processes. (c) 2008 Elsevier B. V. All rights reserved.